Coming in at #1 this week is Get a Green Beer, a St. Patty’s Day themed virtual gifting application, as you may expect. It’s grown from 0 to nearly 1 million active users in the last week alone.

“Whoever receives the most green beers by the end of St. Patrick’s Day (March 17th, 11:59pm PST) will receive $50 towards the purchase of your favorite 12 pack or anything else you want,” the application claims.

Also continuing to rise this week are NCAA tournament bracket apps, as Selection Sunday is close at hand. Watercooler’s 2009 Bracket Challenge has crossed 350,000 active users this week, while Citizen Sports’ Bracket Challenge has crossed 200,000. These apps are likely to grow much more next week as sports fans start building their brackets and making their picks.

Meanwhile, this week’s “hockey stick award” goes to Streema Radio Tuner, up from 7,000 to 150,000 active users in the last week. Streema is a social radio tuner app that lets users listen to a bunch of radio stations and share them with their friends.

As always, check out the latest info on who’s rising and falling on the Facebook Platform at AppData.